1. Field of the Invention
The present invention relates to a circuit breaker and, more particularly, to a circuit breaker which has a prolonged life.
2. Description of Related Art
Many circuit breakers are known. FIG. 4 shows one which includes a shell (40) having an open top and a closed bottom, with a hollow button (50) pivotally connected to the shell (40) at the open top, and a first blade (41), a second blade (42) and a grounding prong (43) extending out of the shell (40) through the closed bottom.
The first blade (41) has an inner end formed with a first contact (411), and the second blade (42) has an inner end pivotally connected to a curved metal piece (60) which is formed with a second contact (61) of platinum. A helical spring (54) is compressed between the hollow button (50) and the curved metal piece (60).
Furthermore, the hollow button (50) receives an indicator light (51) having a first terminal (52) and a second terminal (53). The first terminal (52) is electrically connected with the helical spring (54), while the second one (53) is engagable with the ground prong (43).
Normally, the blades (41, 42) are connected to each other by the curved metal piece (60), and the indicator light (51) is lit up by an electric current through the spring (54), the indicator light (51), the terminals (52, 53) and the grounding prong (43).
In this conventional circuit breaker, however, a problem arises that the terminal (52) and the grounding prong (43) are engaged with each other in a way of point contact, which means a very small contact area between these engaged parts (52, 43).
The small contact area leads to a high contact resistance, which usually brings about electric sparks and oxidation about the point of contact, and so the circuit breaker has a relatively short life.
Therefore, it is an objective of the invention to provide a circuit breaker to mitigate and/or obviate the aforementioned problems.
The object of the present invention is to provide a circuit breaker which has a prolonged life.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.